Leak Check

Fuel Injection Volume, Fuel Injector Leakage And Spray Pattern Of Injectors, Checking


Checking For Leaks
- Bridge sockets 1 and 65 on the test box using test leads from VAG1594 A connector test kit. (This creates an Ground (GND) connection to one side of the fuel pump relay coil.)


NOTE:
Once the socket are bridged the fuel pump runs continuously, even if the engine is not running. This is because the fuel pump relay receives its positive voltage supply via the central electrics. The negative voltage supply for the fuel pump relay comes via the cable bridge on the test box.


WARNING!
Fire hazard. DO NOT smoke or work near heaters or have anything in the area that can ignite fuel!


- Check injectors fuel for leaks (visual check). When fuel pump is running, only 1 or 2 drops should escape per minute from each injector.
- If fuel loss is greater, switch off fuel pump (remove bridge) and replace faulty injector.


Checking injection quantity







- Place fuel injector which is to be tested into measuring glass from injection quantity tester VAG1602.







- Connect one fuel injector terminal to engine Ground (GND) using test cable and crocodile clamp from VAG1594 connector test kit.
- Connect second fuel injector terminal to B+ using remote control VAG1348/3 A, adapter cable VAG1348/3-2 and auxiliary cable.


WARNING!
Make sure test box is inside of passenger compartment


- Bridge sockets 1 and 65 on the test box using test leads from VAG1594 A connector test kit. (This creates an Ground (GND) connection to one side of the fuel pump relay coil.)

The fuel pump should run.
- Activate remote control VAG1348/3 A for 30 seconds.
- When all three fuel injectors from the first bank of cylinders have been activated, place the three measuring glasses on a level surface.
Specified value for each fuel injector: 135... 165 ml
- If measured value for one or more of fuel injectors is outside tolerance range, switch off fuel pump (switch ignition off) and replace faulty fuel injector.
- Repeat test for fuel injectors from second bank of cylinders.
- If measured values for all fuel injectors are outside tolerance range (specification), check fuel pressure Testing and Inspection


NOTE: When checking the injection quantity, also check the spray pattern. The spray pattern should be the same for all the injectors.


Installation of the fuel rail together with injectors is performed in the reverse sequence. The following points should be noted when installing:
- Replace O-rings at all opened connections. (When replacing the front O-ring, make sure not to remove the plastic cap from the injector head. The O-ring must be pulled off over the plastic cap.)
- Moisten O-rings with clean engine oil.
- Make sure fuel injectors are correctly positioned, insert vertically into fuel rail and secure with retainer clips.
- Position fuel rail together with injectors (properly secured) against intake manifold and press into place evenly all round.
- Replace hose clamps and make sure that they are securely installed.